The Guadiana International Bridge (Spanish: Puente Internacional; Portuguese: Ponte Internacional) is a bridge that crosses the Guadiana River connecting southern Spain (town of Ayamonte) and Portugal (town of Castro Marim). It is not split evenly between the two countries, with a greater share of it situated in Portugal. Completed in 1991, its structural type is a cable-stayed bridge, with a deck of prestressed concrete. The bridge is open to vehicles only.
The bridge is 666 metres long with the central span between the towers being 324 metres. The deck stands 20 metres above the river, allowing the navigation of ships of deep draft. The two towers of the bridge are 95 and 96 metres tall, respectively. The Spanish side tower rests on an artificial island built on the riverbed, while the pillar on the Portuguese side is on land.
The bridge connects the Via do Infante de Sagres A22 motorway in Portugal to the Autopista del Quinto Centenario A-49 motorway in Spain, and is part of the European route E01.
es:Puente Internacional del Guadiana Further detail at Spanish Wikipedia.
There are two major classes of cable-stayed bridges: harp and fan.
In the harp design, the cables are nearly parallel so that the height of their attachment to the tower is similar to the distance from the tower to their mounting on the deck.
In the fan design, the cables all connect to or pass over the top of the towers. The fan design is structurally superior with minimum moment applied to the towers but for practical reasons the modified fan is preferred especially where many cables are necessary. In the modified fan arrangement the cables terminate near to the top of the tower but are spaced from each other sufficiently to allow better termination, improved environmental protection, and good access to individual cables for maintenance.
The cable-stayed bridge is optimal for spans longer than cantilever bridges, and shorter than suspension bridges. This is the range where cantilever bridges would rapidly grow heavier if the span were lengthened, and suspension bridge cabling would not be more economical if the span were shortened.